Re: [PATCH v2] compat/bswap.h: simplify MSVC endianness detection

> On 2020-11-10 at 00:31:27, Jeff King wrote:
>> On Sun, Nov 08, 2020 at 11:57:41AM +0200, Daniel Gurney wrote:
>> 
>> > Modern MSVC or Windows versions don't support big-endian, so it's
>> > unnecessary to consider architectures when using it.
>> 
>> This made me wonder if we support any non-modern versions (which would
>> be negatively impacted).
>
> I'm pretty sure we don't.  As I said, we're using several C99 features
> and that version precedes the C99 standard (and 1999).
>
>> From the earlier thread at [1], it sounds like probably not, but I
>> wonder if we can offer a stronger argument there (or just define
>> "modern" a little more clearly).
>
> According to Wikipedia[0]:
>
>   Visual C++ 2013 [12.0] finally added support for various C99 features
>   in its C mode (including designated initializers, compound literals,
>   and the _Bool type), though it was still not complete. Visual C++ 2015
>   further improved the C99 support, with full support of the C99
>   Standard Library, except for features that require C99 language
>   features not yet supported by the compiler.
>
> The version mentioned that supported MIPS, Alpha, and m68k was Visual
> C++ 2.0 RISC Edition.  While Wikipedia doesn't mention its release date,
> its successor, Visual C++ 4.0, was released in 1995.  The m68k version
> ran on Macs using those processors, and Apple abandoned m68k for PowerPC
> in 1994[1].

> I'm entirely comfortable with requiring that people use a compiler and
> operating system newer than 25 years old to compile Git correctly.  As
> I've said or implied in previous threads, I'm also fine requiring C99
> (vendors having had over two decades to implement it) and only
> supporting OSes with vendor security support, although obviously these
> latter two items are much more controversial.